Abstract: Specimens were collected from sick or dead ducks from 9 aquatic farms of 5 provinces in China. 67 suspected strains were purified and then identified by VITEK-32 as E.coli．The results of bacterial susceptibility experiments by the broth micro-dilution test indicated that the tested bacteria presented 56.7%, 71.6%, 31.3%, 49.3%, 50.7%, 71.6%, 62.7%，0% and 56.7% resistance to Ceftriaxone Sodium, Ceftiofur, Cefepime, Cefotaxime, Levofloxacin, Ciprofloxacin, Gatifloxacin, Imipenem, Aztreonam, respectively. The resistant condition of the duck E.coli to the above-mentioned drugs was severely and cross-resistance between analogues should not be neglected.

Key words: pathogenic Escherichia coli from duck; antibiotics susceptibility; resistance; cross-resistance